Tests / Unittests (Maybe more of a "to hack" on topic, but It would be cool if we could make better use of them)

Keyword system to tagging unstable software:

Gentoos emerge uses "accept keywords" to categorize versions of software into either stable, testing or experimental.

I'd like to propose a similar (but simpler) system for emerge on Windows: Add a "keyword" parameter to installation targets. If empty / not existant (current situation) that means "safe" (stable). Potentially unstable packages could then be tagged as potentially dangerous by giving them a certain keyword (like "~").

An emerge configuration option would be needed that defines the keywords that the user accepts (per default, that'd be empty - accepting all current targets but not those marked as unstable).

Developers that want to run bleeding edge software could just add the "~" keyword to the list of accepted ones and instantly move up to all the latest releases (which also makes sense as they might depend on each other).

This simple approach would not have any regressions or require a large initial "tagging" effort but would allow developers in the future to mark potentially dangerous targets leading to a nicer experience for e.g. app developers that "just want a stable base to start from".